Jar



Aug. 3l, 1937. J. R. GREENLEE JAR Filed Feb. 1s, 1935 INVENTOR.

ephRGreenZ,

BY 'R D ATTORNEY.

w B l i @lh I l I .I .I a l Patented Aug. 3l, 1937 UNITED STATES PATENTOFFICE 6Claiml.

This invention is a jar adapted to release a well string when stuck in awell bore, or to impart a jarring blow to a drill bit when drilling inhard formation; and has for its object to actuate the jar byelectromagnetic means.

More particularly it is the object of the invention to provide a jarcomprising a body adapted for incorporation in a well string and formingan anvil, and a cooperating harrmier adapted for reciprocation in thebody to strike the anvil, the hammer being reciprocated byelectromagnetic means.

It is a further object of the invention to incorporate the jar in adrill string so that when the jar is not in use drilling may progress inusual manner, with the drill string and the jar adapted for unobstructedcirculation of drilling fluid both when the jar is inoperative and whenit is in use.

It is a still further object of .the invention to provide simple meansfor transmitting electrical energy to the jar, the transmission meansbeing readily run into the well string and connected to the jar when thelatter is to be operated, and being as readily disconnected and removedwhen the jar is not in use.

It is a still further object of the invention to provide electromagneticmeans for actuating the hammer, preferably adapted to alternatelypositively elevate and lower the hammer for alternately striking upwardand downward jarring blows, with a control for the electromagnetic meansarranged whereby at the will of the operator the hammer may be onlypositively elevated (being, lowered simply by gravity) so as to strikeonly upward jarring blows.

It is a still further object oi' the invention to provide a constructionwhereby tension may be maintained on the well string while striking thejarring blows, an arrangement which is particularly advantageous whenreleasing a stuck well string, in that an upward strain may be exertedon the string while it is being jarred loose.

Further objects of the invention will be readily understood from thefollowing description of the accompanying drawing, in which:

Fig. 1 is an axial section through the ,lar incorporated in a drillstring.

Fig. 2 is a diagram of the electromagnetic means.

Fig. 3 is a transverse section on the line 3 3 of Fig. l.

Fig. 4 is an enlarged axial section through the contact plug for thepower cable.

'I'he jar comprises a tubular body adapted for (Cl. Z55-27) 5 The bodypreferably comprises a plurality of tubular sections having threadedconnections for conveniently assembling the jar; and in the illustratedembodiment wherein an electromagnet elevates the hammer and anelectromagnet is 1 also provided for positively lowering the hammer,tubular sections I 2 for the electromagnets are connected by a tubularsection 3 which forms vertically spaced upper and lower anvil surfaces 45. A sub 6 extends upwardly from sec- 1 tion I and carries contact meanswhereby an electric cable may be connected to the jar; and a sub 1depends from the section 2 and supports a wash pipe 8 which extendsthrough the jar. The threaded connections for these various sections ofthe body are shown at 9.

The sub 6 at the top of the body is suspended from the upper portion Aof a well string, for examplea string of drill pipe, by means of a usualthreaded coupling I0, and the sub 1 at the lower end of the body isconnected by threaded coupling Ila to the lower portion B of the wellstring.

An electromagnet I 6 is mounted in section I, being preferably wound ona spool I1 which is held in place between abutment surfaces formed bythe proximate ends of sections 3 6; and in similar manner anelectromagnet I8 is mounted in section'2, being wound on a spool I9which is supported between abutment surfaces formed by the proximateends of sections 3 1. The wash pipe 8 extends through the bores ofspools I1 I9 and throughy the sections 3 1 with its upper end threadedinto the bore of section 6 as shown at Il and its lower end dependingfrom section 1 and adapted toreceive a nut Il for holding the wash pipein place.

The hammer comprises a head 2l slidable on pipe l in an enlarged bore 22of section 3, and having upper and lower striking surfaces 2& 24 whichrespectively cooperate with anvil surfaces 4 5. Sleeves 25-26respectively project upwardly and downwardly from head 2| and areslidable on the pipe 8 in the bores of spools I1 I9; and the sleeves25-26 are cores which are respectively attracted by the electromagnetsII I8 when the latter are energized. The core 25 together with itselectromagnet I6, and the core 28 together with its electromagnet I8,thus constitute solenoids for actuating the hammer.

leads from the socket through a transverse bore 32 which is formed inthe sub. The cable exltends downwardly through a vertical bore 33 in thesub, and thence through the electromagnet I6 and through a bore 34 inthe section 3. As shown at Fig. 2. thewires 35-36 of the cable areconnected to the respective electromagnets I6-I3, with the opposite endsof the electromagnets grounded on the body of the jar as shown at 31-38.

In the illustrated embodiment ofthe invention the socket is ofinsulating material as shown at Fig. 4 and supports contact sleeves40-4I, insulated from one another at 42 and connected to the respectivewires 35-36. A plug 43 is adapted for reception in the socket 30. andcomprises contacts 44-45 insulated from one another as shown at 46, andrespectively making electrical connection with the contacts -4I when theplug is inserted in the socket. are connected to the contacts 44-45, andextend upwardly through a cable 49 from which the plug 43 is suspended.The plug 43 is run into the drill string on the cable 49; and the cableis prefb erably weighted as shown at 50 and the mouth of socket 30 maybe ared as shown at 5I, to insure the plug seating in the socket.

Circulation is provided around the socket 30, and for this purpose thebore of sub 6 may form an enlarged chamber 55 surrounding the mouth ofsocket 30 and communicating with the circuflation bore of drill stringA, and bores 56 may extend downwardly through sub YIl from the chamber55, with the bores 56 communicating via a chamber 51 with the lower endof the bore of sub 6 which in turn communicates with the wash pipe vIi.The wires of cable 49 are connected to a suitable source of electricalenergy; and the circuits through the wires 41-48 for the respectiveelectromagnets are adapted to be alternately made and broken. For thispurpose suitable switch mechanism may be provided at the earths surface,and the cable 49 is wound on a suitable reel (not shown) whereby thecable may be run into the drill pipe for making electrical connectionsat the plug and socket 43-30, and at the top of the well bore the wires41-48 lead from the cable to the switch mechanism via any usualconnections (not shown). I

The switch mechanism may be of the type shown at Fig. 2, comprising apivoted arm v6I) having contacts ISI-62 at its ends cooperatingrespectively with contacts 63-64. Electromagnets 65-66 cooperate withthe respective ends of the pivoted arm, so that when alternatelyenergized the arm is rocked to alternately make and break the contactsISI-63 and at the same time alternately break and make the contacts62-64. The electromagnets 65-66 may be respectively energized by localcircuits 61-68 and 61-69, the local circuits having brushes 10-1I whichcooperate with a commutator 12. The commutator may be rotated by a motor'I3 through gear reduction 14, and has circumferentially spaced contactswhereby rotation of the commutator alternately energizes the localcircuits. The wires 41-48 are connected to the contacts' 63-64, and oneside of a power circuit leads to the arm 60 as shown at 16 and thencethrough the arm to its Wires 41--46 contacts 6I-62, with the other sideof the power circuit grounded as shown at 11.

The arm 60 being oscillated by the rotation of commutator 12, a powercircuit is closed through electromagnet I6 via 16, 60, 6I, 63, 41, and35 and at the same time the power circuit for electromagnet I8 is brokenat 62--64 (see Fig. 2); and

then the circuit for electromagnet I6 is broken at 6I-63 and the circuitfor electromagnet I8 is closed via 16, 60, 62, 64, 48, and 36. Theelectromagnetsv I6I8 are thus alternately energized, and the frequencyof alternation is preferably adjustable at the will of the operator.This is accomplished by varying the speed of rotation of commutator 12,which may be done by employing a manually controlled variable speed gearreduction 14.

The electromagnets I6-I8 being alternately energized, the electromagnetI6 will rst attract its armature 25 so as to elevate hammer 2| and causeit to strike an upward jarring blow against anvil 4; and whenelectromagnet I6 is 'subsequently deenergized and electromagnet I8 isenergized, the latter will attract its armature 26 and positively lowerthe hammer so that it strikes a downward jarring blow against the anvil5. The operation is then repeated, due-to the continuing oscillation ofarm 60.

If it is desired to strike only upward jarring blows the circuit forelectromagnet I8 is left open, as for example by opening a switch 8D inthe wire 48. When energized, the electromagnet I6 will thus elevate thehammer to cause an upward jarring blow, but when the electromagnet isthen deenergized the hammer will drop simply by gravity without strikingany appreciable downward blow, ready to be again elevated when theelectromagnet I6 is againv energized.

It will also be apparent that if only upward jarring blows are desired,the electromagnet I8 and its power circuit may be completely eliminatedwhen constructing the jar.

In operation the jar is incorporated in a well l string and the cable 49may be withdrawn while the jar is not in use, with unobstructedcirculation via the bores 56 and the wash pipe 8. When it is desired tojar the well string, the cable 49 is run in until plug 43 seats insocket 30, vand the leads 16-11 are connected to a suitable source ofelectrical energy. The motor 13 is started, and the -gear reduction 14is adjusted to provide the desired frequency of jarring blows, theswitch 80 being closed if both upward and downward jarring blows aredesired, or the switch 80 being opened if only upward jarring blows aredesired. During the jarring action circulation may be continued via thebores 56 and the wash pipe 8, and tension may be maintained on the wellstring throughout the jarring action if so desired.

The invention thus provides for electromagnetically operating a jar soas to strike positive upward and downward jarring blows or only positiveupward blows, with the frequency of the jarring blows readilycontrolled, and with the electromagnetic means readily connected to asuitable source of electrical energy whenever the jar is to be used. '4

The invention also provides a jar which may be employed for releasing awell string which has become stuck in a well bore, or for imparting ajarring action to a drill bit during the drilling operation.

It will also be apparent that the electromagnets Iii- I8 may be of atype adapted for operation by direct current, or may be of a typedesigned for operation by alternating current, the proper type ofelectromagnets being selected in accordance with the availableelectrical energy.

I claim:

1. In a jar, spaced anvils, a hammer, and a pair of electromagnets eachadapted to be energized and deenergized, one of said electromagnets whenenergized being adapted to move the hammer in one direction to strikeone of the anvils, and the other electromagnet when energized beingadapted to move the hammer in the opposite direction to strike the otheranvil.

2. In combination, a body, an anvil associated with the body, a hammer,electrical means associated with the body for operating the hammer tostrike the anvil, and an electrical contact for said means mounted inthe body and adapted for releasable engagement by a cooperating contactof an electrical power transmitting cable.

3. In combination, a body adapted for incorporation in a Well string, ananvil associated with the body, a hammer, electrical means associatedwith the body for operating the hammer to strike the anvil, and anelectrical contact for said means mounted in the body in alinement withthe bore of the well string, the body having a bore extending around thecontact and communicating with the bore of the well string, and thecontact being adapted" for releasable engagement by a cooperatingcontact of an electri cal power transmitting cable which extends throughthe bore o1 the well string.

4. In a jar, spaced anvils, a hammer, operating means supported by theJar and adapted to move the hammer in one direction to strike one of theanvils, and operating means supported by the :lar and adapted to movethe hammer in the opposite direction to strike the other anvil.

5. In combination, a well string, a body, means for suspending the bodyfrom the well string so that upward strain exerted on the well string isimparted to the body, means for connecting the body to a dependingelement so that upward strain exerted on the body is imparted to saidelement, an anvil rigid with relation to the body, a hammer movablelongitudinally with relation to the body and the well string, andelectromagnetic means supported by the body for elevating the hammer tostrike an upward jarring blow against the anvil.

6. In combination, a well string, a body, means for suspending the bodyfrom the well stringso that upward strain exerted on the well string isimparted to the body, means for connecting the body to a dependingelement so that upward strain exerted on the body is imparted to saidelement, an anvil rigid with relation to the body, a wash pipe extendinglongitudinally through the body, a member in the body slidable on thewash pipe relative to the body and the well string and including ahammer and a core, and electromagnetic means supported by the body andco-` operating with the core for elevating the hammer to strike anupward jarring blow against the anvil.

JOSEPH R. GREENIEE.

